I am going to try the Administrator idea posted below. Right-clicking and choosing Run as Administrator did not work.

Side note: About three months ago, I installed Flash CS4 and Photoshop CS4 64 bit. Both gave similar problems. I found a thread on the web somewhere suggesting that Google Desktop was the culprit. I do not have Google Desktop installed, but in desperation I uninstalled Google Toolbar and that did the trick. I was able to install. SO this time I tried uninstalling it again, but no luck. I only mention in the interst of providing as much data as possible. Thanks.

Me too. Nothing works. I tried downloading just the Premiere tryout. When I tried to install

it, it installed Encore or Soundbooth, I am now not sure which one I was part of my four above. But same error when it got to premiere. I tried enabling the Admin account like the posters above suggest, tried installing, (this time shows only three uninstalled products: PR, AE, PS) but still nothing.

Ok I discovered the reason for my situation, the admin trick was not necessary. What happened was - I moved My Documents folder to a different drive and then changed the drive letter, so CS5 installer couldn't find My Documents. Since this was a fresh install, I reinstalled Win 7 and got all drive letters sorted out. This is probably different from your situation, but just letting you know, the Admin rights was not the reason.

This error is showing up for a lot of people with Windows 7 x64. Basically, the setup program can't find the payloads (the files used to install the various components). It doesn't matter whether you have a fresh install or whether you log on with a "true" administrator account. The setup is broken and Adobe needs to fix it. The same problem occurs with AE CS5 and PPro CS5 and it doesn't matter whether you install as a trial or an upgrade either. I suggest that everyone file support tickets with Adobe, like I did and maybe they can figure out the commonality.

Try moving it to the drive root. I had my trial copy nested all the way in my downloads folder and kept getting the same error. I moved it to the root of another drive, so the folder path was E:\Adobe CS5 and it installed all the way through, problem free.

To file a support ticket, click on the support link on this page's main menu. There are phone numbers there. The level of support, depends on your product and whether either you or your organization have paid Adobe for a more comprehensive support plan.

The other thing that I noticed is that the install fails almost immediately. If you look in the various install logs (C:\Users\username\AppData\Local\Temp), the Microsoft Installer has this error:

Since that's a MS Visual C library that needs to be installed, apparently, everything else after that fails. The CS5 installer is trying to modify a key in the Windows registry and it either can't find it or it doesn't have permission to modify it. I checked the info in the error code and that key number in my Registry (the big long number) does correspond to that specific MS Visual C library. Why the error says "unknown" instead of the exact key name may also be a problem. In any case, it's a bug in the installer. BTW, installing the library manually works, so it's something that Adobe is doing.

Well as we know the of course does not always mean what it appears to mean.

Hw about running the uninstaller for the trial and then cleaning you stuff in the application support folders, cache, and so on.

I've tried every possible combination, including what you suggested and it does nothing. There is also a CS5 cleanup program available. I've run that and it does nothing also. My guess is that the CS5 installer is making some assumption about Windows 7 x64 installations that is not universally correct. I sent my CS5 Installer log files to Adobe with the Adobe Support Advisor, so I think we will just have to wait and see what Adobe Support can figure out.

Disable firewall/virus protection, run as adminstrator, log in as administrator, disable Fireworks, install the mentioned Microsoft VC files manually pre-isntalltion attempt. Then I did a complete clean install cleaner than this, the system won't be. There is not much software to kill for me: I've bought this PC just 3 days ago, except for Acrobat pro extended I've had no other Adobe software on it yet.

I've also had a go at the CS4 Master collection and lo and behold: the initializing installing ends after 90 % to never resume again.

I have done pretty much everything I can think of, checked the common files which were mentioned a lot in the error log - everything looks fine. The admin has the rights it should have....

Right now I just feel extremely stupid of having invested in a new system in order to fully utilize the CS5 MC and not even the CS4 will install under 64 bit.

Logged a case to support with a variety of error logs and support keys generated by the support advisor.

I give up for now. I have submitted a case with tech support, but since they work M - F, I will have to wait till then. I have tried Administrator, Turn off Firewall, Turn off AV, Run in compatibility, move to C Drive, Install just one product, download just stand-alone Premiere, etc. etc.

Nothing works. It simply refuses to install. So I think the earlier poster that said it is an Adobe issue is probably right.

However, I am about to try one last thing. I have another machine in here that I just bought Win 7 for. So I am going to go try and install it there and see what happens.

I'm also not able to install a download of Master Collection. I get to "checking configuration" and get an "error(20)" code. I'm wondering if despite my best efforts to assemble the folder structure as intended from the multiple downloads, I'm getting it wrong. Would someone who has successfully installed the full CS5 Master Collection from download kindly post a screen shot of the decompressed setup folder structure?

My setup: Win 7 64 bit on a 980X, 12GB RAM. Previously had CS4 MC (uninstalled and cleaned) and a Vendor Prerelease of CS5 MC (uninstalled and cleaned). I even rolled back to a system image from before the prerelease.

Thanks in advance for any help.

EDIT: Success! At least somewhat...by moving each piece of the suite (core apps and various content packs), I got a basic install to work. the core suite setup went without any apparent errors, whereas the content packs warned that Windows had an impending reboot. I'd seen that in the Vendor Prerelease version and ignored it; the content seemed to install fine from there.

Would still like Adobe (or anyone) to clarify the proper, most efficient way to organize and install files, though. Maybe I'm missing the boat, but it does seem that we are left to figure out a multi-Gig install on our own. The suite install PDF was pretty generic in its description of the process.

My other computer in the house is a Dell XPS 420. I purchased a new HD, in

stalled it in the extra bay and installed Windows 7 64bit on this drive creating a dual boot machine. I only installed Windows, MS office and Roxio CD software on this OS. I did ALL the patches and updates.

Time to install CS5 Production Premium. I turned of AV, FW, right-clicked the installer and told it to install as XP-SPIII and Administrator and copied install files to local C Drive first. (Don't know if I needed all of that, but I wanted to be sure). Then I held my breath, and double-clicked the installer.

Away it went. After a while the screen came up success! No errors. Just like it should be right?

Soooo, I have it working on one machine. But still would really like to figure out how to make it work on my primary machine. Thanks.

That is what I think it is a conflict of some kind and perhaps plug ins was he wrong word.

Third party software that interacts or alters the way the system works. perhaps you have font manager that has some alter effect on the system.

Do you understand what I mean. You might all be using software for a similar reason that does something to the system that was not encountered previously.

Trouble shooting fonts would be to turn them all off except the necessary ones and then try to install but unless you have different fonts than you do on the computer you were successful with then I would say that is not the issue.

I woud think it is something different from one computer to the other and you pointed out you only loaded a certain number of other software.

I think you have found the problem but have not pinpointed the culprit, although the culprit might be totally innocent.

But knowing what is causing the conflict will help you install it as well as for Adobe and or the other developer to do something about it.